Sierra WWAN LTE Modem EM7305 does not work after Suspend/Resume

I need some help with getting my WWAN modem to work after Supsend/Resume.

This is a Fujitsu U904 with a Sierra EM7305 LTE WWAN modem running Fedora 26 with Gnome. It works perfectly when the laptop is freshly booted. However, it consistently stops working after a Suspend/Resume cycle. It is then either listed as "unavailable" in the top right menu or it is not listed at all (no Wireless Broadband entry).

I've also tried this with Live versions of Suse Tumbleweed and Ubuntu 16.04 and 17.10. It is exactly the same with these.

Below is the output from lsusb, usb-devices and debug output of ModemManager. There is an error at the very end of the ModemManager debug output which I suspect points in the right direction: